The present invention relates to the field of instrumented rolling bearing devices, particularly used for two-wheeled vehicles, and in particular for the front wheels of motorcycles.
The present invention relates more particularly to an instrumented rolling bearing device intended to be mounted between a shaft and a rotating wheel hub, and equipped with an assembly for detecting rotation parameters such as the angular position, the speed and the acceleration.
Document FR-A1-2 871 881 discloses a device for detecting rotation parameters of a wheel provided with a rolling bearing comprising an outer ring, an inner ring and a row of balls arranged between said rings, with a sleeve onto which the inner ring is mounted, and with a sheath surrounding the outer ring. The device also comprises an encoder mounted on the outer ring and a sensor embedded inside a wire terminal which is mounted on the sheath.
The disclosed device has the drawback of using an elastic driving member between the outer ring of the rolling bearing and the wheel hub to rotate said outer ring by friction contact.
In fact, this rolling bearing is not used for supporting the wheel hub, but only for detecting rotation parameters of the wheel. To this end, the rolling bearing is axially disposed between the wheel hub and a fork arm of the wheel.
Otherwise, particularly during rainy weather, splash pollutants are likely to enter the device, and pollution of the device by external elements may adversely affect the operation of the detection elements.
To protect against polluting elements the encoder and the sensor, it is thus necessary to foresee a seal between the outer ring of the rolling bearing and the sheath surrounding said ring. This is detrimental in terms of mounting time and of cost.
In another field, such instrumented rolling bearings are also known, particularly from WO 01/07922. The disclosed rolling bearing comprises a sleeve secured to the inner ring, a sensor unit fixed to the outer ring and supporting a sensor, an encoder member mounted on the inner ring, and a terminal for leading out wires for communicating the electric signals emitted by the sensor.
This instrumented rolling bearing is not useful for motorcycle wheels operating in an aggressive outdoor environment due to the presence of various kinds of pollution, such as splashing water, dust and other foreign matter, and where it is necessary to be able to reliably measure the rotation parameters.
FR-A1-2 839 349 discloses an instrumented rolling bearing useful as bearing for pulleys which are submitted to difficult environmental conditions, and comprising a seal mounted on the sensor support and pressing against the outer surface of the outer ring.
This instrumented rolling bearing is not satisfactory in terms of cost and of mounting time because an additional seal is used. Besides, the seal creates a friction between the parts of the rolling bearing.